My edivence for that headcanon:
1) Americanizing racial minorities was a pretty common thing back at the 1800s and 1900s. They were taught English and how to act in the white dominating society, even their names were turned Anglo-Saxon. A member of a racial minority could get a better job and a great livehood, if they had education and recommendations, and were “white enough.” As a humanist, Jack London handled also racism in his books. His sinophobia was questionable, though...
2) There came lots of Finns (mostly young men, but there were women, too) to the US at the time, mostly because of the better oppornuty to get a job and guarantee their families’ welfare. They were experts in tree felling, so that’s why they moved to states like Minnesota, Michigan and Wisconsin. (And Canada.)
3) Despite their white skin color, Finns were targets of racism and harrassment daily. To Americans’ eyes, Finns weren’t considered to be part of “the master race” for their culture and behavior.
4) Indians found things lots of common with Finns: Love to nature, sauna/sweat tent, high use of alcohol, hunting for food, poem songs and cyclical time concept based on the cycle.
5) Frona was born in Dyea, in the middle of nowhere, and her love towards the wilderness was deep.
